1. Field of the Invention
The present invention relates to centrifugal pellet dryers in which centrifugal action is used to separate water from polymer pellets incorporating unique structural and functional features including but not limited to utilizing the pellet outlet nozzle as an air inlet, feeding the pellet/water slurry upwardly from underneath the dryer directly into the lower end of the rotor of the dryer, providing a sloped bottom in the dryer to facilitate ease of cleaning, providing a hinged cylindrical screen encasing the rotor to enable the screen to be removed for easier cleaning, closing the top of the dryer and using the pellet outlet for the air inlet which will eliminate flat spots in the pellet outlet to make it easier to clean and eliminate cross contamination which occurred in previous dryers as pellets frequently ricocheted or bounced into the air inlet filter housing and later fell back into the dryer, providing large panel doors to facilitate cleaning and constructing the dryer housing with flat sides which provide more versatility in the location of connections and enabling the dryer housing to be of double wall construction for receiving insulation to reduce noise.
2. Description of the Prior Art
U.S. Pat. No. 3,458,045 issued to Vernon E. Dudley on Jul. 29, 1969 and assigned to the same assignee discloses a centrifugal pellet dryer for separating water from polymer pellets and drying the pellets. U.S. Pat. No. 4,896,435 issued to Melvin B. Spangler, Jr. on Jan. 30, 1990 and assigned to the same assignee also discloses a similar dryer with replaceable components and other improvements. Centrifugal pellet dryers of this type having an air inlet in the upper end portion, a slurry inlet and a pellet outlet for dried pellets together with a rotor and screen assembly have been manufactured and used for many years. In addition to the above two patents, other centrifugal dryer structures are known in the following patents.
U.S. Pat. No. 892,502 PA1 U.S. Pat. No. 2,934,830 PA1 U.S. Pat. No. 4,156,392 PA1 U.S. Pat. No. 4,176,465 PA1 U.S. Pat. No. 4,504,222 PA1 U.S. Pat. No. 3,385,443 PA1 U.S. Pat. No. 2,727,631
While the above mentioned patents disclose centrifugal dryers, they do not disclose the specific unique structural features and functional advantages incorporated into this invention as discussed in the preceding paragraph.